Method and apparatus for reclaiming sheet metal



Feb. 6, 1940. c. D. CROUS E ET AL 2,139,573,

METHOD AND APPARATUS FOR RECLAIMING SHEET METAL r v Fi led Feb. 26, 1938 //VVEN7'0AS C/mr/es 0 6704/56 4/14 (/0/1/1 Marika Patented Feb. 6, 1940 METHOD AND APPARATUS FOR RECLAIMING sneer METAL Oha'rlesD. Crouse and John F. Marshall, West Alexandria, Ohio, assignors to Porcelain Strip Mills, Inc. 7

Application February 26, 1938, Serial No; 192,828

- v 2 Claims.

This invention relates toa method and apparatus for reclaiming sheet metal and particularly toreclaiming the metal content 'of' porcelain enameled sheets.

lain enameled'sheet metal parts in. the manufacture of furniture and household appliances, such as refrigerators, cook stoves, cupboards,

7 cabinets, etc, and the fact that the process of apficiently diflicult to result'in a considerable number ofimperfectly covered parts which are not permitted to be used in the finished product, it is becoming a difiicult problem to dispose of the rejected material.

Ordinarily, metal parts rejected in manufacture are accumulated and remelted for use in the manufacture of new sheets, but sheets having a porcelain enamel coating are not usable in this manner, ;first because of thedeleterious effect on the furnaces in which they must be melted, and second because of the influence the porcelain has on the-remelted metal itself.

Due. to the fact that the process of' coating sheet metal with porcelain enamel comprises fusing the vitreous coatingand the metal sheet together, it has up to this time been'found impractical to remove all of the enamel at the low cost necessary to warrantthe operation in view of the metal salvaged thereby, with the result that manufacturers oiporcelain sheet metal products have either resorted to the expedient of hauling this rejected scrap over long distances to places where it was acceptable as filling for 37 low ground. or of purchasing land adjacent the manufacturing plants, where the price was not prohibitive, for permanent use as a dumping ground.

It is therefore an object of this invention to provide asimple and inexpensive method which will completely remove a porcelain coating which is fused to a sheet of metal. v

, It is another object to provide simple and inexpensive apparatus to carry the method into effect.

6 In the course of experimentation to evolve a suitable method of carrying the object, of this invention into effect, it was found that although bending a plurality of waves in the sheet at short intervals, at given spot being bent first convex then concave, hada considerable influence in removing the porcelain coating, a greatly improved result was had when the same process was repeated on the sheet with the waves made to extend at right angles with respect to the first waves.

Owing to the rapidly, increasing useof porce 2,

plying the porcelain cover to sheet metal is suf- Further experimentation, however-, disc1osed that a vastly improved result was attained when the surface of the sheet was stretched to a considerably larger area than its original area, whereby the grain of the metal, itself was eX- panded so as to release the tentacles of the por celain which were imbedded therein.

The method may therefore consist in one 01 more of a plurality of-steps comprising bending, stretching, or, bending and stretching of the sheet to remove the porcelain, and the apparatus may comprise a means for carrying out several or all of the steps mentioned, preferablyin a continuous cycle. One embodiment of such apparatus is now disclosed, reference being made to the accompanying drawing, wherein Fig. '1 is a top plan view of the apparatus Fig. 2 is a longitudinal vertical section taken at 2-2 of Fig. 1.

, Fig. 3 is a fragmentary section taken at ,3-3 of Fig. 2 showingthe corrugating surfaces of two of the rolls.

Similar numerals refer to similar parts throughout the several views.

Construction In the drawing the frame l0 carries a series of journal boxes in which pairs of rolls are rotatably supported. The first paircomprising the rolls l4 and I8 are smooth round rolls, without grooves or corrugations, rotatable in journal boxes l8 and geared together to rotate in unison by a pair of duplicate gears 20. i

The second'pair, comprising rolls 22 and 24, each has axially spaced grooves 26 extending cir- .cumferentially around it, the grooves of one'of l the pair meshing into the ridges 28 which separate the grooves of the other. This pair is rotatable in the journal boxes 30 the two rolls being geared together to rotate in unison by the pair of duplicate gears 32. In the drawing part only of the rolls 22 and 24 are shown providedwith the grooves 25 and ridges 28 but it will beun'derstood that in practice these rolls are provided for their entire length with grooves like those shown. 5

The third pair comprising rolls 34 and 36, each 1 has a series of circumferentially spaced grooves 35 extending lengthwise of the roll parallel to its axis of rotation forming an equal number oi teeth it between the grooves, the teeth of one 5 of the pair meshing into the grooves-of thejother. This pair is rotatable in the journal boxes 44 the two'rolls being geared together by the'duplicate gears to cause them to rotate at the same speed,

While the drawing shows grooves 38 and teeth 40 covering part only of the circumference of the rolls it will be understood that the entire circumferences of the rolls 34 and 36 are provided with these grooves and teeth.

The fourth pair comprising rolls 52 and 54 are substantially duplicates of the second pair 22 and 24, except that they may preferably be slightly larger in diameter and the total number of ridges 28 may be several more or several less in the length of the rolls 52, 54 than in the rolls 22, 24 so that the spacing may be different in one pair than in the other. They are rotatable in journal boxes 56 and geared to rotate together by the duplicate gears 80. .The fragmentary cross section Fig. 3 shows how the ridges 28 of one roll fit into the grooves 26 of the other.

Gears 20, 32, 50, and 80 are drivably connected by idler pinions 64, B6, and 68. Secured to the pinion 64 to revolve therewith is the large gear 10. A pinion 12 having rotative bearing in the hub '14 meshes with the large gear 10. A pulley 16 is secured to the pinion 12 to rotate therewith. Any suitable source of power, none shown, may be belt connected to pulley 76 to drive the rolls, the arrangement being such as to cause all of the rolls to revolve in the same direction.

A pair of wire scratch brushes 18 and 8B are rotatable in journal boxes 82. These brushes should preferably revolve much faster than the rolls and are therefore provided with small pulleys 86 which may be belted to a suitable source of power. Adjusting screws 83 are provided to adjust the rolls for different thicknesses of sheets and for different pressures therebetween. A table 90 is provided to support the sheets in a horizin tal position when starting them through the first pair of rolls.

Operation The porcelain coated sheets to be reclaimed are laid on the table 9G and started between the first pair of rolls l4 and I6. Since a great many enameled sheet metal parts are drawn or other wise formed to curved surfaces, these rolls operate principally to flatten out the sheets before they reach the second pair of rolls. It will therefore be understood that when the machine is being operated exclusively on sheets which are already fiat, the first pair of rolls are preferably removed and the sheets initially fed into the second pair of rolls.

As a sheet passes through the second pair of rolls, the grooves and ridges 26, 28 of the rolls, form a series of alternate ridges and furrows in the sheet. Due to the pressure between the rolls and the resulting friction between the rolls and sheet, the sheet does not get appreciably narrower. It follows that, after the sheet has passed through these rolls, while the linear measurement from edge to edge of the sheet remains at the original dimension, the actual surface measurement across the sheet when following the cross sectional contour down into the furrows and up over the ridges has been greatly increased by stretching the metal.

The sheet next passes through the third pair of rolls 34, 36 which corrugates it crosswise. This has the effect of partially removing the longitudinally extending ridges and furrows previously made and the further effect of slightly widening the sheet. It also bends a given spot in the metal in a different direction than that in which it was bent by the first rolls.

The slightly widened sheet next passes through the fourth pair of rolls 52, 54 which again stretches the metal crosswise to again provide the longitudinal ridges and furrows. If the rolls 52, 54 have been made slightly larger in diameter than the rolls 22, 24, the tendency will be to stretch the metal somewhat lengthwise of the sheet. If the grooves 26 and ridges 28 of rolls 52, 54 have been spaced slightly different from the grooves 26 and ridges 28 of the rolls 22, 24, the metal will be more apt to be bent at different points when passing through rolls 52, 54 than it was when previously passing through rolls 22, 24. The furrows now extend in the right direction to have the completely loosened and broken up porcelain brushed out by the rotating scratch brushes I8, 80. I Y

It will of course be understood that in cases where one side of the sheet stock only needs to be cleaned, one brush may be removed, or, when the need for thorough cleaning is not so great, both brushes may be omitted. The first pair of rolls l4, it, as before stated, may be removed when all of the sheet stock being run is already substantially without curved surfaces. more it would be practicable where a low priced apparatus was desired, and the quantity of stock to be reclaimed was relatively small, to use apparatus containing one pair of rolls as 22 and 24 and a second pair 34 and 38 without any of the other rolls whereby the sheets would be bent and stretched into furrows and ridges first in one direction of the sheet then in a direction at right angles to the first direction, or, the single pair of rolls 22, 24 could be used alone if the sheets were 1 run first lengthwise, then crosswise through such rolls.

Any other apparatus which operates 10 remove the porcelain by increasing the surface area of the sheets or by bending the sheet or by a combination of both bending and stretching is considered within the spirit of the claims to the apparatus herein set forth, and any method comprising bending, stretching, or a combination of the two within the spirit of the method claims which follow.

We claim:

1. The method of salvaging the metal content from porcelain coated metal sheets which consists of pressing a series of ridges and furrows in the sheet, next forming similar ridges and furrows crosswise of the first, next forming similar ridges and furrows crosswise of the second, the last said ridges and furrows being of different spacing from the first, whereby the porcelain is broken loose from the metal, separating the porcelain and metal then removing the broken porcelain by scratch brushing the sheet lengthwise of the last made furrows.

2. Apparatus for removing an enamel coating 1 from a metal sheet, said apparatus comprising, in combination, a series of rollers to press separate series of furrows one after the other in the sheet as it passes therethrough, each series being crosswise of that next preceding, to thereby loosen Further- 

